post 121
 

That's keeping 'em honest magic. Somebody has to patrol the troops or the inmate's will run the asylum.

Actually it was Magic who missed the point of a perfectly logical and informative post. Thanks BGrey! Link fixed!:D

Yesterday I was browsing this thread and others for instruction.

There was a tutorial that showed how to intercept a ship that's out of your sight range... like 8 hours away.

In the tutorial, the ship was headed WNW and you intercept it from the east. It had a good narrative that went with it, saying that you calculate the time to intercept at about 8 hours, then go off to bed... but then you remember that you want to get there early, so you raise your speed by 1 knot, then go back to sleep.

This is the most I can remember and I can't find it anywhere now. Can anyone help me?

Thanks in advance!

Might that be Dantenoc's tutorial? Look here: http://www.subsim.com/radioroom/showthread.php?t=88961

That's it!

Thanks. I can tell I'm gonna like this place.

Fastest method to determine the target true course?
 

Can I determine the true course of the target via the TDC only...after I take a couple range/bearing readings and calc/enter the speed...:06:

I would think that two range/bearing checks would plot two spots that could be connected automatically in the TDC and the course thus determined.

Or is the only way to determine course by plotting two points on the chart and drawing the true course on it?

What is the fastest method to estimate the true course..

I've watched the videos on how to use the TDC for all targeting set ups.

Mike:)

How to sort through all the sonar returns to target somebody
 

So you see a convoy on the plotting map....

How do I determine the range to a single target ship using sonar, can I somehow pick out the ship I'm pinging?

Need to do this to determine course and speed, but not sure how to pick out one via sonar to do that. Perhaps I have to use either radar or periscope to do that?

Mike

Well, hey there! Thanks for dropping by. Pull up a chair and feel free to pull yourself one of those semi-adult beverages over there whilst I dig up a couple answers here:

Well, if all you want to do is take a couple of range/bearing observations and not plot them on the chart (why would you want not to use a plot?) there is a way to find the course and speed using only the TDC. Our game developers crumbled to repeated requests and included a calculate speed and course button on our TDC. I think that's a tragedy, but here's how it works.

You take two different stadimeter readings of range/bearing at least 10 seconds apart. Then you proceed to the speed input mode of the TDC input dial and press this button:

http://i196.photobucket.com/albums/a...peedbutton.jpg

Now your accuracy is strictly dependent on the accuracy of your two observations and is rendered more accurate by increased time between observations. Keep in mind that stadimeter and accuracy are two words that probably shouldn't be allowed to occupy the same sentence.

With radar, using the plot and actually measuring the distance between two positions three minutes apart, drawing the course and measuring it is a technique that will give you MUCH more reliable information on all parameters, speed, course and range.

The fastest method of determining true course is to spend an unreasonable amount of time playing with gutted's Solution Solver, quizzing yourself with his AoB sight determination gillhickey on there. With MUCH practice you can do like the real sub skippers used to do: sidle up to the periscope, take a gander and intone "Angle on the bow 47º starboard." As long as an accurate bearing is in the TDC, entering the AoB will cause the target's bow on the output dial of the TDC to point to that AoB. You'll notice an outside ring of numbers there also. They are the true course, which you can read outside the AoB number. WernerSobe's video on manual targeting explains and shows this process.

Well, that's the good news. The bad news is that picking out a single sonar contact in a crowd is pretty impossible. Contacts have to be several degrees apart to resolve them as individuals. Even when you can resolve them, how do you know you are picking up the same one for two different pings? Even with continuous monitoring (which would keep you from skippering your sub, most un-commander like) two contacts could cross and you could be following a different one for your second ping. The verdict: sonar only is not suitable for convoy situations.

Boy, this is gonna turn out to be a bit longer than expected. Guess I'm full of questions today, but you've been given fair warning. ;)

Actually, RR, that brings up one of the only gripes I have about SH4, and some historians 'round here might even set about proving me wrong and showing that it's accurate, but here's the skinny: I've always been frustrated as all get out that I have commands for 'report nearest contact' and 'follow nearest contact,' but no 'follow current contact.' (Ideally, would be used identically to follow nearest, but would rely on the current hydrophone bearing to pick up the initial contact) Assuming that you're facing a light convoy, perhaps a few little merchies with a pair of DDs in a flanking escort, there should certainly be a point where it becomes viable to track a single sonar contact. I've done it myself many a time for TMA in unfavorable conditions where it's either too muddled to see squat, or too clear to risk exposure, so as far as SH4s mechanics are concerned, I see it as viable, prima facie.

Now, though, the test; are the sonar mechanics modelled with enough accuracy in this case that such a task would have been feasible? Of course you're going to get a fair bit of interference for long-range convoy intercepts, but I'm concerned primarily with low-volume surface traffic, not rushing headlong into a carrier TF bound for Midway. If it does seem plausible enough, does anyone know if there have been any efforts to implement this via modding? It seems a bit silly to jump back and forth from my comforting protractor and compass to continually take hydrophone bearings to complete my TMA plot. Almost started pulling my hair out when I spied a large modern composite cruising along in an otherwise unremarkable mini-convoy, but my soundman was only interested in the DD playing catchup from behind my juicy freighter-snack.

I'm certainly not opposed to having realistic situations where you could lose a sonar track from ships crossing (though I doubt the engine allows for that much flexibility) but the exclusion of a seemingly-obvious feature like this has always stumped me.

---

On another note, I've still been playing stock for some time, and I think I'm finally hitting the cusp where I'm confident enough in my approach and intercept tactics to take on Ducimus' DDs. I do, however, want to finish out my career (And maybe squeeze in a few S-boat excursions for kicks and grins) but there are a few 'secondary' mods I recall hearing about but no clue what they might be called. Before I make the transition to full-fledged TMO/RSRDC, I intend to grab TMOkeys to speed up the inevitable learning curve, and get my grubby paws on the 360d bearing plotter as well. One thing I've never much cared for is the impeccable accuracy of my hydrophone crew when it comes to giving me exact ranges from passive listening. I share the opinion that 'map contacts off' is just about as silly as the uber-contacts in place by default, so I'm still hunting for that happy medium. One of the mods I read about in passing, as I understood it, converted all sonar contacts into extended dashed lines, and it sounds like it's right up my alley for the balance I'm looking for. Anyone have a name I can go drum into the mods page?

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Final question (Promise!) any special concerns that pertain to running JSGME on digital distributions? (STEAM in my case). I know where all the relevant program directories and such are, but just wanted to make sure that there weren't any special considerations for electronic editions.

Thanks in advance for puttin' up with me! :arrgh!:

First of all, that's what this thread is for: good questions like yours. So let me take my time and go through these.

Yes, a follow current contact instruction would be VERY logical. In an unambiguous situation, that would save us a lot of grief as our brain-dead operator keeps switching targets to the closest warship or just the closest enemy vessel, depending on your orders. Heck, he doesn't even do that reliably. Actually, he should be able to follow a current contact while still retaining the ability to advise you of new developments that could change your orders.

Were that idea implemented in the game, we would then be talking about how the sonar operator is so perfect in a convoy situation, able to continue following a single target even when you couldn't pick him out if you were using the sonar yourself. Every silver lining has its cloud, you know, and Ubi could have turned this into another iteration of perfectly plotted visual sightings and plotted passive sonar spikes whose lengths tell you the range.

Now, if you think about it, the MOST confusing situation would be a small convoy of merchants. Why? In a warship convoy, you have many different types of target, all with different sounds... Well, not in SH4 because we only have two sounds: merchant and warship. These are played at a finite variety of speeds to convey slow, medium and fast. That's why we can't do turn counts, which is good, because WWII subs really couldn't convert turn counts to speed either because they didn't have sufficient data on non-warships to do so.

In a merchant convoy, you are more likely to be dealing with half a dozen to a dozen identical merchants with no difference in sound to speak of. They are lined up in columns and rows in such a way that even when you are close, the contacts are continually crossing, giving you a random choice, when the single contact divides in two, of which one is your original target. However, let me suggest that you try tracking the closest target in front or at the rear of the convoy. This way, every time contacts cross, when they divide, you automatically pick the front or the back one! I think this should work even in the game as we have it now, so long as the AoB is less than 90º. After 90º, the lead target would always lag the crossing target and the last target would always lead.

That should be no problem, as your plot would show you the parallax situation created by the AoB and you would know what to expect. Is anyone else following my reasoning or am I being way too abstract here?

Along with grabbing TMOkeys (which you will like much better than the stock keyboard layout, once you are used to it. I bet you'll use it even if you stick with the stock game), you might also grab TMOplot, which will let you play with the TMO plotting system. TMO tosses out the ship silhouettes, the target ID text, and the friend/foe/neutral colors. That's why I only found out I sank the USS Essex after I returned to port. That's why I fired the torpedo. I had no silhouette telling me it was an aircraft carrier and it wasn't green. Result: bustin' rocks! What's not to like?:haha:

As far as the passive sonar spikes telling you the position of the target, why plot those points? I just note that particular target seems louder than the rest and leave it at that. Certainly a competent sonar operator would tell you that. He would also tell you that local listening conditions could mean that the loudest contact is not really the closest, but we are talking about an imperfect game here. I treat it just like I treat visual sightings. Plotting positions and making speed and course measurements are a no-no for those two categories of info in SH4.

I look at having sonar spikes extended to the edge of the screen as the same thing as turning map updates off: the solution is worse than the problem when a little discipline in not taking measurements from those positions is all that is needed. After all, in real life that competent sonar operator is making decisions about what information to pass on to you as commander based on his assessment of which are the closest targets of concern.

I am running JSGME with a Steam installation of Left 4 Dead (amazing how all those other games use the brute force method of mod installation. Dummies!) and it works flawlessly. I've also used it with a non-Steam installation of Grand Theft Auto: San Andreas and it worked marvelously there too.

Awesome thread here :yep::up:

Thank you RDP. Yours is the praise I value most highly here at Subsim as I rate you consistently the most positive and helpful member here both before and after you became a moderator. Salute!:salute:

Hello Yall,
I am sure you guys know this by now, but if not, here goes. There are 2 things I have noticed in SH4.
1) If you are playing the German side, you can access the map, as you would in SH3 by clicking on the map, but only if you put the crew at "battle Stations," then click on the guy standing by the map (yes the navigator), and then point camera at map, and clickon the map. Also each time you zoom in or out of the map, and look at the map, it shows the last level of zoom you were just looking at.

2) Again, the Germans. The G7es (Falke Torpedos) are slow, and were the first homing torpedos. I know you know this, but if you load one or two in the aft tubes, and A destroyer is a bother, get it to chase you from behind. If he is going 12kts or faster (very likely if he saw you), then line him up in the scope, as close to 180 as you can, then that slow homing torpedo works miracles. Good by destroyer. Don't forget to shut off your engines so the torpedo can find its mark easier. Thats it.

3) This is not a trick, but a even though, you guys will probably like it, so enjoy. http://www.uboat.net/gallery/index.html

There have been several threads lately about problems with planes in Silent Hunter 4, especially with TMO. These posts are quickly followed by advice on how to cheat and modify the configuration files to minimize or eliminate airplanes. I'm sure that's exactly how Dick O'Kane handled the planes.... Let me flatly state that planes in SH4 and in TMO are not a problem and if you are running your sub properly they cannot ever see you and cannot ever attack you unless you are attacking a convoy at periscope depth and get VERY unlucky.

Planes are not a problem if you handle them right. You don't have to and it isn't helpful to stay submerged all day or even for an hour after sighting one. All that does is discharge your batteries so you aren't combat ready.

Remember, a submarine is a surface boat with the unique ability to submerge when absolutely necessary, and to stay submerged for the absolute minimum amount of time. With airplanes, that means about 10 minutes total per plane. Our goal is to travel at maximum fuel economy speed, 9 knots, on the surface so we have 100% charged batteries available to fight at all times.

Let me explain. First of all, this strategy needs air search radar, a pretty common thing on American submarines. When a plane is first spotted on radar, you have several minutes of decision time. Let's use them! A couple of planes just showed up. What are they up to?

I immediately draw a 5 mile radius circle around my sub. That's my danger zone. If the planes enter that zone, they can possibly see me. My goal is never to be seen by a plane, EVER. That means no John Wayne popgun ineffectually giving away my position so the pilot can call his good buddies to the party and I'm swarmed for several days. I'm not going there. If a plane can possibly see me I'm pulling the plug.

OK, we have the visibility danger circle around the sub. Now, from the position of the plane, draw two lines from the plane(s) to both outsides of the circle (tangent lines).
http://i196.photobucket.com/albums/a...154.46_390.jpg

Not every plane is going to enter your danger zone. If it does not we want to stay on the surface. 100% battery charge at all times you know... With our "ice cream cone" chart, we can easily tell with plenty of time whether this bad guy is going to be a problem. If he stays outside the cone, we're golden. If he crosses the line to the inside it's time to initiate avoidance.

At that point our goal is to be at or below periscope depth when he crosses the circle line of our danger zone. Pick a number below 100', I always just use about 110, your mileage may differ but I haven't had a problem with that and full-blown TMO. As you cross periscope depth, start your stopwatch. When it reaches 5 minutes, press surface ("s"). Do not dawdle around at periscope depth looking for planes. He's gone. No buddies not previously spotted on radar have had time to enter your danger zone. Your combat awareness is 100%. You are safe. Just get up there and resume surface travel.

You haven't been spotted. No little flyboy buddies will be checking you out. Also, I run around at best fuel economy, about 9 knots all the time. during my plane avoidance drill I don't touch the throttle. I submerge normally, none of this crash dive silliness, because you have plenty of time. Have you ever crash dived, surfaced and reentered time compression not remembering you were at full throttle? It'll make you cranky! Don't do it. Following my procedure it can never happen.

Planes are not an issue in TMO. They are not a threat. They cannot ever see you. The only thing that can hold you down is an escort. And if you didn't follow my airplane avoidance strategy, you're not ready for them because you have low batteries. You're a dead duck. Why would you care whether you were killed by a plane or by an escort. Wouldn't you rather not be killed by either?:D

Good advise RR, I remember seeing this same advise in one of your videos and have "never" had a problem with airplanes in TMO by following this advise. One problem I had early in my careers was cruising at too high of a TC rate and allowing the planes to get inside that 5 mile circle before TC reset to normal, not allowing enough time to know what was happening and get to below 100'.

One other problem I had early was not going to 100'+ and allowing the planes to see me at periscope depth, planes do see you so get deep. But don't waste time going to 450' it is a waste of time, 100+ works just as well and saves time on going down and up.

In plane infested areas, I'm usually cruising around at TC about 500 to 1000x. When a plane is sighted, I step it down to 8 or 16x while I figure out where he's headed. I'll step it down to 8x if he's approaching the danger radius, leave it at 16x if he's going to pass harmlessly by and leave it there until he's at least 10 miles off, going away. Then I resume 500 to 1000x.

If I have to dive I leave it at 8x, hit the dive key (not crash dive) in time to be at or below periscope depth as he crosses the line, start the stopwatch, step up to 16x until 5 minutes are up, hit "s" to surface and after I'm surfaced I'll go back to 500 or 1000x.

What would the optimal TC rate be then to get the most TC, with the best time for it to switch back to normal?

I have never had a problem at 1k TC, at 1.5k TC you better be quick to the keyboard to get down, after that it is a crap shoot.

Probably between 128 and 1k then :03:

I'm going with 128 TC max on my way to recon Osaka.

Hey guys! I was innocently stalking another thread on authentic methods of speed measurement in a pre-radar submarine. Someone popped up with the time the length across the wire method, which for some reason is very popular on Subsim. I'm afraid I blasted that great method as completely historically bogus.

So we talked about using bow wave and then stern wave to estimate speed. That works well, and in the game it's very reliable with experience. It was also used during the war.

But I was looking for a more analytical method, because that's my personal character defect :D, and ended up looking through the Submarine Torpedo Fire Control Manual from 1946 (link later). It was so great that it belongs here in your bag of tricks! It's amazing what happens when you look at what the real submariners did. There sure weren't stupid!